Hemochromatosis, Hereditary

Tests with long turn-around times (ie. Molecular based tests and Microarrays) should only be requested on an inpatient if the result is going to affect the inpatient management.

If the patient will likely be discharged before the result will be available, the test should be requested after discharge. (NOTE: UCSF Medical Center is not reimbursed for inpatient testing).

An exception to the above may be appropriate if there is a possibility the patient will not survive to be discharged and the information is important for diagnosis and/or family decisions/management (ie. recurrence risk).

Test code

HHEM

Performed by

Medical Genomics - Molecular Diagnostics

In House Availability

Run 1x per week as needed, Tuesday or Thursday, day shift only

Method

PCR and allele-specific probes

Collection Instructions

If collecting in citrate, check the expiration date on the label of the blue top vacutainer before drawing the patient.

Do not collect sample in heparin. Keep sample refrigerated for overnight or longer storage.

An interpretation of this test by a laboratory physician will automatically be performed and billed for separately.

The Cys282Tyr (G845A, C282Y) mutation in the HLA-H gene is found in 85% of the chromosomes of patients with Hereditary Hemochromatosis.

Homozygosity for the C282Y or compound heterozygosity for C282Y and H63D mutations is associated with increased risk of iron overload. Despite the high frequency of the C282Y mutation the clinical penetrance of the homozygous C282Y genotype is estimated to only be 1-4% (Beutler, BE, Blood 101:3347, 2003)

Heterozygosity or homozygosity for the H63D mutation does not appear to be clinically significant but may ben associated with elevated serum transferrin levels. (Gochee, et al., Gastroentroology 122:646, 2002)

Results are reported as "No Mutation Detected", "Heterozygous for Mutation" or "Homozygous for Mutation".

If a mutation is detected it is recommended that the patient seek genetic counseling.

Note: This test was developed and its performance characteristics determined by the Clinical Laboratories at the Medical Center at UC San Francisco. It has not been cleared or approved by the U.S. Food and Drug Administration.

See also Iron, Transferrin and Transferrin Saturation and Iron, Liver.